In Critically Ill Patients Requiring CRRT, AKI Is Associated with Increased Respiratory Failure and Death Versus ESRD

Background/aims: To compare outcomes of critically ill patients with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) versus those with pre-existing end-stage renal disease (ESRD) requiring CRRT to identify factors that contribute to the increased mortality seen in AKI patients. Methods: Retrospective cohort of 257 intensive care unit (ICU) patients who received CRRT. AKI is defined as requiring CRRT with an admission serum creatinine <= 1 mg/dL; ESRD is defined as chronic dialysis dependence. Primary outcome was hospital mortality. Multivariate logistic regression was performed to determine the impact of APACHE II score, intubation, vasopressors, infection, diabetes, hypertension, gender, and race on mortality. Results: Of 257 patients requiring CRRT, 28 had ESRD and 108 had AKI. Hospital mortality was higher in patients with AKI versus ESRD (69% vs. 39%, p = 0.0032). Severity of illness using APACHE II was similar in AKI and ESRD. Patients with AKI were more likely to require mechanical ventilation (89% vs. 57%, p = 0.0003). After multivariate analysis, the requirement for mechanical ventilation was the single factor associated with increased hospital mortality [odds ratio (OR): 3.1]. Conclusions: In ICU patients requiring CRRT, patients with AKI have a higher mortality than patients with ESRD due to an increased need for mechanical ventilation.